Snap action switch



July 15, 1952 W F, AUER 2,603,727

SNAP ACTION SWITCH Filed NOV. l5, 1950 V M mmn \\\\\\\\\\\\\\\\\\\\\\\Wl Hlllllllllll Il 16/ 17B /nor.

Patented July 15, 1952 UNITED STATES y--PA'EN'I -,-OFFICE f y `v t'l-12,603,727rf t 'ff' .,zfgf

sNAPAc'rIoN SWITCH t v 'Wiuiam'mie eicel-6,111.,assignortd Y YRaymond'T.- Moloney, Chicago, Ill. a Application Ndvexibei 13, wsa'sriiA195,337' A v The, presentdisclosures pertain to improvements in a snapiactinl switch relating principally to a new type ofj over-center orsnap-'action two-point rocking' seat on' the" operator j blade withthethirdjpoint of 4 suspeitisionon the. movable bladesituatedin'triangular array with' the other two points. y The foregoing objectsand Will become apparent as thev following descrip'- tion proceeds inview' of the annexed drawing, in which:

Fig. 1 is a top plan view of the improved switch; Fig. 2 is a sideelevation of the same; Y

Fig. 3 is a magnified vertical section of the snap-action part kof .theswitch Fig. 4 is a sectional view like th'atof Fig. 3, but showing thesnap mechanism actuated; Y

Fig.,5 is a perspective detail of the new bow spring; Y Y v Fig. 6 isA aperspective fragment of the overpassing operator blade for thebowspring.

Theptype of switch to which the improvements are applied forillustration herein is commonly known as a stack switch, which, as seenin Fig. 2, consists of a stack of insulating wafers generally indicatedat I0, between which are clamped (by action of bolts and nuts II) a pairof relatively rigid flanking or outer contact blades I2 and I3.

Mounted in the stack to flex between said flanking contacts I2 and I3,is a thin springcontact blade I4, having at its outer or free end asmall tongue I (Fig. 3).

An over-center bow spring I6, such as shown in Fig. 5, made from thinflat metal stock or ribbon, is provided at one of its ends with a smalldiepunched slot IBA intertting with tongue vIiito provide one of theendwise rocking mounts or three-point assemblies of the spring with theexible or movable contact blade.

At its opposite or remaining end, the bowk spring is somewhat wider thanthe adjoining spring stock, and has punched in the widened part acut-out, for instance, in the form of otherr f of novelty and utilityinherent in the improvements y a claims. (emot-.67.)

(Fig. `5l an arcuate transverse slot` IBB iianked" byopposite siderwings IBC whichv aftordar1 -Y expanse of metal stock to provide theopposite 01T- vhe wings and offsets IEC-IBD constitute a pair ofyrockersat the outer 0r remote vside of the The assembly is ompleted byprovisionof anI operator bl'ade'I'I, also flexible, and as seen in Fig.6having a central eut-out IIA large enough to permit vup and downflexing ofgrthe moyable and-down past4 the Acontact blade, byfreasonoffreet en'dfo'f the` `iiexiblev contact blade- ,'Illjf'the op-vadmitthrocker formations ogoffsets; TI SCI lfili).Y

axis'of'the'bladejsofas to afford' astraig'ht knife-Y end-"oi thebow'spring relative to the operatori' bow spring IS urging the movablecontact down- Wardly against the lower stationary contact I2.

When a downward pressure is applied to the free end of the operatorblade I'I so as to displace the latter from the condition of Fig. 3'toward the operated condition of Fig. 4, the operator blade is seen toover-pass the contact blade I4, and the bow spring I6 will passreversely into an overcenter relation to its mounting at I-5A-I6A withthe movable contact blade, and abruptly reverse its thrust to urge themovable contact I4 up-v wardly into the snap-operated condition shown inFig. 4, the opposite end parts IC--IBD of the bow rocking easily in atwo-point seating in notches I'IB in such action.

Actually,` the bow spring has a three-point suspension in which thepoints of suspension are in a triangular array, one point on tong I5 andthe other two in notches IIB. When the operating required in mountingthem in operative position; -j y Also the snap-action is satisfactory inbothne and coarse throws of the movable blade, as where Y contacts I2and I3 are spaced relativelyiarlapart or close together.

The improved construction requres. no inter- K Vmediate moving orconnecting partsy between eitherV the bow and the movable contaot,=orthe ,1'

bow and the operator blade; and the two-point site sides of'the operatorblade affords a greatly enlarged area of rocking sup-port for thebowspring in the region where its displacement is greatest, while at thesame time the bow is very secure against accidental dislodgement, itbeing noted in this connection, also, that the Acurved or forked cut-out16B prevents any upwardmovement of thebow spring which-might disengagethe latter fromritsl rocking seat.`

Once assembled, the bow spring is practically locked in position in itsthree-point suspension. The novel construction is also advantageous inthat it Yis, equally effectivewithlvery shortcon-7 tacts |2-I3,-l4,orthelonger blades'frequently emp1yed.- o.. l., v

Ienimzf 1. In al snap switch of the type having Yamovf` ablecontactblade cooperable with an over-passing operator blade,improvements,comprising, to`

witg'over-center snap-action spring means in the form of a bow of flatspringmetal, one end kof said bow being enlarged and having a transversecut-out'withv its opposite side portions terminat-4 ing inoifsetsconstituting a pairofrockers, said operatorblade having a pair oftransversely--` aligned edgewise f ulcrum notches each receiving andseating-oneof said rockers with said cut-out underlying vthe transverseregion of the blade between said notches, the opposite Aend 'of saidbow' being supportably engaged iorslight movement with an end portion ofsaid movable blade.

2.In a snap-action switch of the known type which includes a ilexiblecontact blade with an over-passing operator-blade and a lsnap-acting 4 4over-center spring interposed operatively between a free end portion ofthe contact blade and a confronting part of the over-passing blade,improvements comprising, to wit: improved over-center spring meansincluding a bow spring having one end forked with a cut-outA portion todene two prongs, said prongs being offset to afford a pair of laterallyspaced rockers flanking said cut-out portion, said over-V-.passing'bladehaving a pair of laterallyf-spaced notches "in `which ,said vrockers arerespectively received, the opposite end region off` said spring beingsupportably engaged with said free end portion of the contact blade, soas Vto be compressible by movement of the operator l lao`le relative tothe contact blade, said cut-out portion being of va depth tocleartheoperator `blade in operational movements of the latter.

3. In a snapf switch of the known variety which includes an elongatedcontact blade xed at one end and free to be flexed from its oppositefree end, snap-action means comprising: an elongated operator blade alsofixed atone .end with said contact blade -and spring-biased to a normalposi-'f tion and also having a central vcut-out whichcan pass over saidfree end of the contactjblade inv leXures of the operator blade, and abowed, flat-i stock over-center spring having tongue and slot engagementat one of its ends with said free end of said contact blade, and havingat its Opposite end `forked with opposite rocker offsetsrockably seatedin edgewise notches in the operator-blade' adjacent the free end regionof the flatter, said bow spring being normally )under compression andacting in over-center snap-action with said movable contact responsiveto operative displace-V ments of said operator blade relative to saidnormal position to throw the movablev contact back.

and forth between normal and operated positions, and stationarylimitingmeans, includingatleast one stationary contact, flanking said movableblade to ydetermine said positions. ,n wILLIAivLF.AUVER.)Vv

REFERENCES CITED UNITED STATES 'eATENTs Q Date

